METHOD FOR CLEANING AN OUTER SURFACE AND USE OF A MULTI-JET ROTATING HEAD IN THE CLEANING METHOD

PROCEDE DE NETTOYAGE D'UNE SURFACE EXTERNE ET UTILISATION D'UNE TETE ROTATIVE A JETS MULTIPLES DANS LE PROCEDE DE NETTOYAGE

English Abstract

The invention relates to a method for cleaning an outer surface (1) arranged at the bottom of a tank (3), a vessel or similar, said method comprising the steps of: generating and supplying a pressurized cleaning fluid by means of a production source (2) of pressurized cleaning fluid, the fluid pressure being between 3 and 12 bar; conveying the cleaning fluid opposite the said outer surface (1) of the tank (3) by circulating the fluid in a pipe network (4) arranged below the tank (3); cleaning the outer surface (1) of the tank (3) by means of a plurality of rotating jets of cleaning fluid, the said plurality of jets being generated by at least one multi-jet rotating head (10) connected to the pipe network (4), wherein conveying of the cleaning fluid is realized by the pipe network (4) forming a closed loop (5) arranged below and near the centre (6) of the outer surface (1) of the tank (3), the said closed loop (5) being supplied with cleaning fluid by a feed pipe (7) connected to the said production source (2) of pressurized cleaning fluid.

French Abstract

L'invention porte sur un procédé de nettoyage d'une surface externe (1) disposée au fond d'un réservoir (3), d'une cuve ou analogue, ledit procédé comprenant les étapes suivantes : la génération et la fourniture d'un fluide de nettoyage pressurisé au moyen d'une source de production (2) de fluide de nettoyage pressurisé, la pression du fluide étant comprise entre 3 et 12 bars ; le transport du fluide de nettoyage à l'opposé de ladite surface externe (1) du réservoir (3) par circulation du fluide dans un réseau de tuyau (4) disposé au-dessous du réservoir (3) ; le nettoyage de la surface externe (1) du réservoir (3) au moyen d'une pluralité de jets rotatifs de fluide de nettoyage, ladite pluralité de jets étant générés par au moins une tête rotative à jets multiples (10) reliée au réseau de tuyau (4), le transport du fluide de nettoyage étant réalisé par le réseau de tuyau (4) formant une boucle fermée (5) disposée au-dessous et à proximité du centre (6) de la surface externe (1) du réservoir (3), ladite boucle fermée (5) étant alimentée en fluide de nettoyage par un tuyau d'alimentation (7) relié à ladite source de production (2) de fluide de nettoyage pressurisé.

Claims

6
CLAIMS
1. Method for cleaning an outer surface (1) arranged at the bottom of a tank
(3), a
vessel or similar, said method comprising the steps of-
.cndot. generating and supplying a pressurized cleaning fluid by means of a
production
source (2) of pressurized cleaning fluid, the fluid pressure being between 3
and 12
bar;
.cndot. conveying the cleaning fluid opposite the said outer surface (1) of
the tank (3) by
circulating the fluid in a pipe network (4) arranged below the tank (3);
.cndot. cleaning the outer surface (1) of the tank (3) by means of a plurality
of rotating
jets of cleaning fluid, the said plurality of jets being generated by at least
one
multi-jet rotating head (10) connected to the pipe network (4) ;
characterized in that conveying of the cleaning fluid is realized by the pipe
network
(4)forming a closed loop (5) arranged below and near the centre (6) of the
outer
surface (1) of the tank (3), the said closed loop (5) being supplied with
cleaning fluid by a
feed pipe (7) connected to the said production source (2) of pressurized
cleaning fluid.
2. Method according to Claim 1, characterized in that the pipe network (4)
comprises a plurality of pipes (8) emerging radially from the said closed loop
(5).
3. Method according to Claim 2, characterized in that each pipe (8) is
straight and
comprises a free end (9) arranged near the periphery (11) of the outer surface
(1).
4. Method according to Claim 1, characterized in that the pipe network (4) and
the
said at least one multi-jet rotating head (10) are each made from a stainless
steel.
5. Method according to Claim 1, characterized in that the pressure of the
cleaning
fluid is between 8 and 10 bar.
6. Method according to Claim 1, characterized in that the cleaning fluid is
water.
7. Use of a multi-jet rotating head in a cleaning method according to any one
of
Claims 1 to 6, in the field of the cleaning of a tank (3), a vessel or
similar.

Description

CA 02796546 2012-10-16
WO 2011/131517 PCT/EP2011/055721
1
METHOD FOR CLEANING AN OUTER SURFACE AND USE OF A MULTI-JET
ROTATING HEAD IN THE CLEANING METHOD
Technical field
The invention relates to the field of cleaning relatively inaccessible
surfaces
generally arranged facing or opposite the ground.
The invention relates more particularly to a method and a use of multi-jet
rotating
heads for cleaning this type of surface, which may be formed by the outer
underside of a
tank, a vessel or similar.
Prior art
In general, such surfaces, due to their limited access, are difficult to clean
and
generally require the use of high pressure cleaning devices for spraying a
cleaning fluid at
a pressure of about 80 bar. An operator moves below the surface with the high
pressure
cleaning device, and, if necessary, can use a motor driven vehicle in order to
cover the
entire surface to be cleaned.
Another conventional solution is to employ nozzles attached to mobile
carriages on
rails. This case has the drawback of the possibility of dirt settling on the
rails, and also
potential derailments. Furthermore, it is necessary to employ reels for the
fluid hoses
(washing liquid, electricity). This creates points that are difficult to clean
in the
installation, and increases the price.
In fact, such surfaces may extend over several tens of square metres with
large-
sized vessels or tanks. Such tanks may in particular allow the germination of
plants or
seeds, or even the fermentation of the seeds in a liquid.
However, this type of cleaning method does not guarantee the complete cleaning
of
the surface. This is because an operator performing the cleaning may fail to
see, and
therefore clean, an area that is relatively inaccessible.
Moreover, this type of device for high-pressure cleaning requires an electric
power
source in order to supply an electric compressor arranged inside the device.

CA 02796546 2012-10-16
WO 2011/131517 PCT/EP2011/055721
2
In consequence, such a type of device may be dangerous to its user, who is
therefore completely immersed in a humid atmosphere and is constantly
spattered with
mud. This type of device thus incurs high risks of electrocution for its user.
Another
drawback is that the hoses drag on the ground for the operator incurring a
risk of falling.
It is therefore the purpose of the invention to supply a safe and effective
solution for
cleaning relatively inaccessible surfaces, located under vessels or tanks.
Summary of the invention
The invention therefore relates to a method for cleaning an outer surface
arranged at
the bottom of a tank, a vessel or similar, characterized in that it comprises
the steps of.
^ generating and supplying a pressurized cleaning fluid by means of a
production source of pressurized cleaning fluid, the fluid pressure being
between 3 and 12 bar;
^ conveying the cleaning fluid opposite the said outer surface of the tank by
circulating the fluid in a pipe network arranged below the tank;
^ cleaning the outer surface of the tank by means of a plurality of rotating
jets
of cleaning fluid, the said plurality of jets being generated by at least one
multi-jet rotating head connected to the pipe network.
The step of conveying of the cleaning fluid is realized by the pipe network
forming
a closed loop arranged below and near the centre of the outer surface of the
tank, the said
closed loop being supplied with cleaning fluid by a feed pipe connected to the
said
production source of pressurized cleaning fluid.
In other words, such a cleaning method serves for the automatic cleaning of
the
outer surface of the tank arranged facing the ground. Such a cleaning can be
carried out
periodically and thus guarantees an optimal state of cleanliness of this
surface.
Advantageously, the rebound of the jets on the cleaned surfaces is exploited
to increase
the impact area and hence the quality of the cleaning.
Furthermore, the number of multi-jet rotating heads depends on the size of the
surface to be cleaned, and on the shape and size of the pipe network arranged
below the
tank.

CA 02796546 2012-10-16
WO 2011/131517 PCT/EP2011/055721
3
The rotary movement of the jets is also automatic thanks to the pressure of
the
cleaning fluid, and requires no electric power supply nor a motor drive. The
pressurized
cleaning fluid drives the rotation of the jet head. Such jet heads provide a
360 indexed
impact cleaning over a defined time period and the flow of cleaning fluid
makes the
nozzles perform a geared rotation around the vertical and horizontal axes,
like, for
example the heads branded under the reference MULTIJET 40 by the Applicant.
The production source of pressurized cleaning fluids may be arranged near the
vessel and be incorporated in a central production unit in order to generate
pressurized
cleaning fluid to supply several pipe networks. In this way, the same
production unit of
pressurized cleaning fluid can be used to clean several juxtaposed tanks.
Moreover, the pipe network connects the closed loop, arranged below and near
the
centre of the surface to be cleaned, and the production source of pressurized
cleaning
fluid.
Such a closed loop may be formed of several straight pipe sections, and
thereby
have the shape of a polygon. Other shapes may be considered, such as circular
or
elliptical shapes in particular.
In practice, the pipe network may comprise a plurality of pipes emerging
radially
from the closed loop.
The number and length of these pipes accordingly depends on the size of the
area to
be cleaned.
According to a particular embodiment, each pipe may be straight and comprise a
free end arranged near the periphery of the outer surface. In consequence, the
pipe
network substantially has a star shape centred with regard to the centre of
the surface to
be cleaned.
Such outer surfaces to be cleaned are generally circular, and in consequence,
the
straight pipes have the same length.

CA 02796546 2012-10-16
WO 2011/131517 PCT/EP2011/055721
4
Advantageously, the pipe network and the multi-jet rotating head may each be
made
from a stainless steel. In consequence, a cleaning installation using this
method requires
no additional manual maintenance that would be performed by an operator and
has very
good corrosion resistance.
In practice, the pressure of the cleaning fluid may be between 8 bar to 10
bar. In
fact, such a pressure combined with a flow rate of about 50 m3/h serves to
optimally clean
the underside of the tank. The inventive method consumes a quantity of water
similar to
that used by a cleaning trolley.
According to a particular embodiment, the cleaning fluid may be water. In
consequence, it is possible to clean the underside of tanks which demand
cleaning without
detergent. Such a cleaning fluid is indispensible in particular for
applications in which
seeds are fermented or germinated in a solution.
Furthermore, and as already stated, the invention also relates to a use of a
multi-jet
rotating head, in a cleaning method as previously described, in the field of
the cleaning of
a tank, a vessel or similar.
Brief description of the figures
The manner for implementing the invention and the advantages thereof will
clearly
appear from the embodiment that follows, provided for information but non-
limiting, in
conjunction with the appended figures, in which:
Figure 1 is a bottom view of an installation for carrying out the cleaning
method
according to the invention.
Figure 2 is a side view of the same installation for carrying out the cleaning
method
according to the invention.
Manner of implementing the invention
As already stated, the invention relates to a method for cleaning an outer
surface
arranged at the bottom of a tank.
As shown in Figure 1, the cleaning method according to the invention serves to
clean an outer surface 1 of the underside of a tank 3. To carry out this
method, a
production source 2 is used to generate and supply a pressurized cleaning
fluid.

CA 02796546 2012-10-16
WO 2011/131517 PCT/EP2011/055721
The cleaning fluid is then conveyed below the outer surface 1 to be cleaned.
Thus,
a pipe network 4 comprises a closed loop 5 arranged near the centre 6 of the
surface to be
cleaned, and a feed pipe 7 connecting the production source to the closed loop
5.
5 Furthermore, straight pipes 8 emerge substantially radially from the closed
loop 5.
Multi-jet rotating heads 10 are connected to the pipe network 4, for cleaning
the entire
underside of the tank 3.
The rotating heads 10 are arranged at the two ends of the straight pipes 8, at
a free
end 9, and at an end connected to the closed loop 5.
Obviously, this number of rotating heads 10 may be adjusted according to the
size
and shape of the outer surface 1 to be cleaned. In general, a rotating head 10
serves to
clean an area of about 250 m Nevertheless such an area is theoretical
considering the
effective range of the jets without blind zones, associated with the columns
and other
cross members. For example, the total area to be cleaned could be equal to 908
m with a
tank diameter of 34 m.
As shown in Figure 2, the tank 3 does not rest directly on the ground, and is
maintained in position at a predefined height by means of columns 21, and
supports 20
resting on the ground.
The pipes 8 may consequently also rest on the supports 20 and therefore do not
require additional support means. As shown, the axes of rotation of the
rotating heads 10
are arranged horizontally in order to clean the outer surface 1 of the tank 3.
It appears from the above that a method and a use of rotating heads according
to the
invention have many advantages, and in particular:
^ they serve to carry out an automatic cleaning of the underside of a tank;
^ they guarantee optimal cleaning of the surface once the cleaning is
completed;
^ they require no maintenance and have a long service life;
^ they can be used for periodic cleaning of the surface at low cost.

Representative Drawing